add conda_python() and virtualenv_python() functions for finding the …

…python binary associated with an environment

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: reticulate
 Type: Package
 Title: Interface to 'Python'
-Version: 1.9.0.9002
+Version: 1.9.0.9003
 Authors@R: c(
   person("JJ", "Allaire", role = c("aut", "cre"), email = "jj@rstudio.com"),
   person("Kevin", "Ushey", role = c("aut"),

NAMESPACE

@@ -79,6 +79,7 @@ export(conda_binary)
 export(conda_create)
 export(conda_install)
 export(conda_list)
+export(conda_python)
 export(conda_remove)
 export(conda_version)
 export(dict)
@@ -145,6 +146,7 @@ export(use_virtualenv)
 export(virtualenv_create)
 export(virtualenv_install)
 export(virtualenv_list)
+export(virtualenv_python)
 export(virtualenv_remove)
 export(virtualenv_root)
 importFrom(Matrix,sparseMatrix)

NEWS.md

@@ -19,6 +19,9 @@ Install the development version with: `install_github("rstudio/reticulate")`
 
 - Support for iterating all types of Python iterable
 
+- Add `conda_python()` and `virtualenv_python()` functions for finding the
+  python binary associated with an environment.
+
 
 ## reticulate 1.9 (CRAN)
 

R/conda.R

@@ -193,6 +193,16 @@ conda_version <- function(conda = "auto") {
   system2(conda_bin, "--version", stdout = TRUE)
 }
 
+#' @rdname conda-tools
+#' @export
+conda_python <- function(envname, conda = "auto") {
+  env <- subset(conda_list(conda = conda), name == envname)
+  if (nrow(env) > 0)
+    path.expand(env$python[[1]])
+  else
+    stop("conda environment ", envname, " not found")
+}
+
 
 
 find_conda <- function() {

R/virtualenv.R

@@ -178,6 +178,17 @@ virtualenv_remove <- function(envname, packages = NULL, confirm = interactive())
   invisible(NULL)
 }
 
+#' @rdname virtualenv-tools
+#' @export
+virtualenv_python <- function(envname) {
+  config <- virtualenv_config()
+  virtualenv_path <- file.path(config$root, envname)
+  if (utils::file_test("-d", virtualenv_path))
+    path.expand(file.path(virtualenv_path, "bin", "python"))
+  else
+    stop("virtualenv ", envname, " not found")
+}
+
 
 virtualenv_config <- function() {